陕北小流域生物结皮空间分布影响因子的通径分析  

Path Analysis of Influencing Factors of Spatial Distribution of Biological Soil Crust in Small Watershed of Northern Shaanxi

作　　者：袁方[1] 张振师[2] 张朋[1] 卜崇峰[1,3] 

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国电建集团西北勘测设计研究院有限公司,西安710065 [3]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持研究》2015年第6期30-35,41,共7页Research of Soil and Water Conservation

基　　金：国家自然科学资助项目(41071192;40701096);中国科学院西部之光人才项目(2014-91);西北农林科技大学科研项目(2014YQ006)

摘　　要：选择黄土高原典型坡面,通过全面调查,采用通径分析方法,研究了生物结皮盖度和厚度的空间特征及其与环境因子之间的关系。结果表明:(1)研究区内,生物结皮在沙土区呈连续分布,平均盖度在30%以上,在黄土区则呈离散的零星分布,盖度大多在20%以下;而其厚度和抗剪强度在沙土区和黄土区的差异不显著(p>0.05)。(2)通径分析表明,土壤质地是影响结皮盖度的直接因子(直接通径系数Psand=0.720),沙蒿盖度是其间接因子(间接通径系数Psh,sand=0.422),两者均对结皮盖度有促进作用,土壤含水率的直接正作用和间接负作用相当,因而总体贡献并不明显,海拔的直接和间接作用均为负;沙蒿盖度是影响结皮厚度的直接因子(Psh=0.329),而海拔(Pele,other=-0.206)及坡向(Pasp,other=-0.311)对结皮厚度的间接负作用最大。(3)土壤含水率、土壤质地、海拔及沙蒿盖度是影响生物结皮盖度的主要决策变量,且土壤质地的直接作用,以及沙蒿盖度通过土壤质地的间接作用是其主要的作用路径;沙蒿盖度、坡向及海拔是影响生物结皮厚度的主要决策变量,且沙蒿盖度的直接作用,以及坡向通过沙蒿盖度及海拔通过硬质早熟禾盖度的间接作用是其主要的作用路径。We chose a typical slope in the Loess Plateau, made a comprehensive survey and used the method of path analysis to study the spatial characteristics of the coverage and thickness of biological soil crusts （BSCs） and its relationship with environmental factors. The results showed that： （1） in the study area, BSCs distributed continuously in sand area, and the mean coverage was generally over 30%, while in loess area, it showed a discrete and sporadic distribution, and their coverage was generally below 20%, but thickness and shear strength of BSCs had no significant differences in the sand and loess area（p〉0.05） ： （2） the path anal ysis showed that the soil texture was the direct factors （Direct path coefficient Psand =0. 720） and Artemisia desertorum Spreng coverage was the indirect factor （Indirect path coefficient Psand =0. 422） which impacted on the coverage of BSCs, both of them had the promotion role in the coverage of BSCs, the direct positive effect and indirect negative effect of soil moisture content were fair, so the overall contribution was not obvious, direct and indirect effects of altitude were negative, Artemisia desertorum Spreng coverage was the direct factors （Psand=0.329） and slope（Pele,other=--0.311） and elevation（Pele,othe=-0.206） had the biggest indirect effect on the thickness of BSCs; （3） soil moisture content, soil texture, elevation and the coverage ofArternisia desertorurn Spreng were the main decision variables of BSC coverage. The direct effect of soil texture and the indirect effect of the Artemisia desertorum Spreng coverage through with the soil texture were the main role of path of BSCs, coverage of Artemisia desertorum Spreng, slope and elevation were the main decision variables of BSCs thickness, the direct effect of Artemisia desertorurn Spreng coverage, and the indirect effect of the slope which was through the Arternisia desertorurn Spreng coverage and the elevation which was through the Poa sphondylodes Trin. coverage were the ma

关 键 词：生物结皮 空间分布 通径分析 影响因子 

分 类 号：S157[农业科学—土壤学]